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<title>Sequitur algorithm</title>
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<h1 id="firstHeading" class="firstHeading mw-first-heading">
<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Sequitur algorithm</span></span>
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<div id="mw-content-text" class="mw-body-content mw-content-ltr" lang="en" dir="ltr"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><p><b>Sequitur</b> (or <b>Nevill-Manning–Witten algorithm</b>) is a recursive algorithm developed by <a href="Craig_Nevill-Manning" title="Craig Nevill-Manning">Craig Nevill-Manning</a> and <a href="Ian_H._Witten" class="mw-redirect" title="Ian H. Witten">Ian H. Witten</a> in 1997<sup id="cite_ref-Nevill-manning1997_1-0" class="reference"><a href="#cite_note-Nevill-manning1997-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> that infers a hierarchical structure (<a href="Context-free_grammar" title="Context-free grammar">context-free grammar</a>) from a sequence of discrete symbols. The algorithm operates in linear space and time. It can be used in <a href="Data_compression" title="Data compression">data compression</a> software applications.<sup id="cite_ref-Nevill-manning1997_2_2-0" class="reference"><a href="#cite_note-Nevill-manning1997_2-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>
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<div class="mw-heading mw-heading2"><h2 id="Constraints">Constraints</h2></div>
<p>The sequitur algorithm constructs a grammar by substituting repeating phrases in the given sequence with new rules and therefore produces a concise representation of the sequence. For example, if the sequence is
</p>
<dl><dd>S→abcab,</dd></dl>
<p>the algorithm will produce
</p>
<dl><dd>S→AcA, A→ab.</dd></dl>
<p>While scanning the input sequence, the algorithm follows two constraints for generating its grammar efficiently: <b>digram uniqueness</b> and <b>rule utility</b>.
</p>
<div class="mw-heading mw-heading3"><h3 id="Digram_uniqueness">Digram uniqueness</h3></div>
<p>Whenever a new symbol is scanned from the sequence, it is appended with the last scanned symbol to form a new <a href="Bigram" title="Bigram">digram</a>. If this digram has been formed earlier then a new rule is made to replace both occurrences of the digrams.
Therefore, it ensures that no digram occurs more than once in the grammar. For example, in the sequence <b>S→abaaba</b>, when the first four symbols are already scanned, digrams formed are <b>ab, ba, aa</b>. When the fifth symbol is read, a new digram 'ab' is formed which exists already. Therefore, both instances of 'ab' are replaced by a new rule (say, A) in <i>S</i>. Now, the grammar becomes <b>S→AaAa, A→ab</b>, and the process continues until no repeated digram exists in the grammar.
</p>
<div class="mw-heading mw-heading3"><h3 id="Rule_utility">Rule utility</h3></div>
<p>This constraint ensures that all the rules are used more than once in the right sides of all the productions of the grammar, i.e., if a rule occurs just once, it should be removed from the grammar and its occurrence should be substituted with the symbols from which it is created. For example, in the above example, if one scans the last symbol and applies digram uniqueness for 'Aa', then the grammar will produce: <b>S→BB, A→ab, B→Aa</b>. Now, rule 'A' occurs only once in the grammar in <b>B→Aa</b>. Therefore, A is deleted and finally the grammar becomes
</p>
<dl><dd><b>S→BB, B→aba</b>.</dd></dl>
<p>This constraint helps reduce the number of rules in the grammar.
</p>
<div class="mw-heading mw-heading2"><h2 id="Method_summary">Method summary</h2></div>
<p>The algorithm works by scanning a sequence of <a href="Terminal_symbol" class="mw-redirect" title="Terminal symbol">terminal symbols</a> and building a list of all the symbol pairs which it has read. Whenever a second occurrence of a pair is discovered, the two occurrences are replaced in the sequence by an invented <a href="Nonterminal_symbol" class="mw-redirect" title="Nonterminal symbol">nonterminal symbol</a>, the list of symbol pairs is adjusted to match the new sequence, and scanning continues. If a pair's nonterminal symbol is used only in the just created symbol's definition, the used symbol is replaced by its definition and the symbol is removed from the defined nonterminal symbols. Once the scanning has been completed, the transformed sequence can be interpreted as the top-level rule in a grammar for the original sequence. The rule definitions for the nonterminal symbols which it contains can be found in the list of symbol pairs. Those rule definitions may themselves contain additional nonterminal symbols whose rule definitions can also be read from elsewhere in the list of symbol pairs.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>
</p>
<div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2></div>
<ul><li><a href="Context-free_grammar" title="Context-free grammar">Context-free grammar</a></li>
<li><a href="Data_compression" title="Data compression">Data compression</a></li>
<li><a href="Lossless_compression" title="Lossless compression">Lossless data compression</a></li>
<li><a href="Straight-line_grammar" title="Straight-line grammar">Straight-line grammar</a></li>
<li><a href="Byte_pair_encoding" class="mw-redirect" title="Byte pair encoding">Byte pair encoding</a></li></ul>
<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>
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<li id="cite_note-Nevill-manning1997-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-Nevill-manning1997_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">
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</style><cite id="CITEREFNevill-Manning,_C.G.Witten,_I.H.1997" class="citation journal cs1"><a href="Craig_Nevill-Manning" title="Craig Nevill-Manning">Nevill-Manning, C.G.</a>; Witten, I.H. (1997). "Identifying Hierarchical Structure in Sequences: A linear-time algorithm". <a href="ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/cs/9709102">cs/9709102</a></span>. <a href="Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1997cs........9102N">1997cs........9102N</a>.</cite> <span class="cs1-visible-error citation-comment"><code class="cs1-code">{{cite journal}}</code>: </span><span class="cs1-visible-error citation-comment">Cite journal requires <code class="cs1-code">|journal=</code> (help)</span></span>
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<li id="cite_note-Nevill-manning1997_2-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-Nevill-manning1997_2_2-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFNevill-Manning,_C.G.Witten,_I.H.1997" class="citation book cs1"><a href="Craig_Nevill-Manning" title="Craig Nevill-Manning">Nevill-Manning, C.G.</a>; Witten, I.H. (1997). "Linear-Time, Incremental Hierarchy Inference for Compression". <i>Proceedings DCC '97. Data Compression Conference</i>. pp.&nbsp;<span class="nowrap">3–</span>11. <a href="CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a>&nbsp;<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.30.2305">10.1.1.30.2305</a></span>. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FDCC.1997.581951">10.1109/DCC.1997.581951</a>. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a>&nbsp;<bdi>978-0-8186-7761-8</bdi>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a>&nbsp;<a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:14324301">14324301</a>.</cite></span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://github.com/GrammarViz2/grammarviz2_src">GrammarViz 2.0 – Sequitur and parallel Sequitur implementations in Java, Sequitur-based time series patterns discovery</a></span>
</li>
</ol></div></div>
<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>
<ul><li><a rel="nofollow" class="external text" href="http://www.sequitur.info/">sequitur.info – the reference Sequitur algorithm implementation in C++, Java, and other languages</a></li></ul>
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</style><div id="Data_compression_methods241" style="font-size:114%;margin:0 4em"><a href="Data_compression" title="Data compression">Data compression</a> methods</div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Lossless_compression" title="Lossless compression">Lossless</a><br>type</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Entropy_coding" title="Entropy coding">Entropy</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Adaptive_coding" title="Adaptive coding">Adaptive coding</a></li>
<li><a href="Arithmetic_coding" title="Arithmetic coding">Arithmetic</a></li>
<li><a href="Asymmetric_numeral_systems" title="Asymmetric numeral systems">Asymmetric numeral systems</a></li>
<li><a href="Golomb_coding" title="Golomb coding">Golomb</a></li>
<li><a href="Huffman_coding" title="Huffman coding">Huffman</a>
<ul><li><a href="Adaptive_Huffman_coding" title="Adaptive Huffman coding">Adaptive</a></li>
<li><a href="Canonical_Huffman_code" title="Canonical Huffman code">Canonical</a></li>
<li><a href="Modified_Huffman_coding" title="Modified Huffman coding">Modified</a></li></ul></li>
<li><a href="Range_coding" title="Range coding">Range</a></li>
<li><a href="Shannon_coding" title="Shannon coding">Shannon</a></li>
<li><a href="Shannon%E2%80%93Fano_coding" title="Shannon–Fano coding">Shannon–Fano</a></li>
<li><a href="Shannon%E2%80%93Fano%E2%80%93Elias_coding" title="Shannon–Fano–Elias coding">Shannon–Fano–Elias</a></li>
<li><a href="Tunstall_coding" title="Tunstall coding">Tunstall</a></li>
<li><a href="Unary_coding" title="Unary coding">Unary</a></li>
<li><a href="Universal_code_(data_compression)" title="Universal code (data compression)">Universal</a>
<ul><li><a href="Exponential-Golomb_coding" title="Exponential-Golomb coding">Exp-Golomb</a></li>
<li><a href="Fibonacci_coding" title="Fibonacci coding">Fibonacci</a></li>
<li><a href="Elias_gamma_coding" title="Elias gamma coding">Gamma</a></li>
<li><a href="Levenshtein_coding" title="Levenshtein coding">Levenshtein</a></li></ul></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Dictionary_coder" title="Dictionary coder">Dictionary</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Byte-pair_encoding" title="Byte-pair encoding">Byte-pair encoding</a></li>
<li><a href="LZ77_and_LZ78" title="LZ77 and LZ78">Lempel–Ziv</a>
<ul><li><a href="842_(compression_algorithm)" title="842 (compression algorithm)">842</a></li>
<li><a href="LZ4_(compression_algorithm)" title="LZ4 (compression algorithm)">LZ4</a></li>
<li><a href="LZJB" class="mw-redirect" title="LZJB">LZJB</a></li>
<li><a href="Lempel%E2%80%93Ziv%E2%80%93Oberhumer" title="Lempel–Ziv–Oberhumer">LZO</a></li>
<li><a href="LZRW" title="LZRW">LZRW</a></li>
<li><a href="Lempel%E2%80%93Ziv%E2%80%93Storer%E2%80%93Szymanski" title="Lempel–Ziv–Storer–Szymanski">LZSS</a></li>
<li><a href="Lempel%E2%80%93Ziv%E2%80%93Welch" title="Lempel–Ziv–Welch">LZW</a></li>
<li><a href="LZWL" title="LZWL">LZWL</a></li>
<li><a href="Snappy_(compression)" title="Snappy (compression)">Snappy</a></li></ul></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Burrows%E2%80%93Wheeler_transform" title="Burrows–Wheeler transform">BWT</a></li>
<li><a href="Context_tree_weighting" title="Context tree weighting">CTW</a></li>
<li><a href="Context_mixing" title="Context mixing">CM</a></li>
<li><a href="Delta_encoding" title="Delta encoding">Delta</a>
<ul><li><a href="Incremental_encoding" title="Incremental encoding">Incremental</a></li></ul></li>
<li><a href="Dynamic_Markov_compression" title="Dynamic Markov compression">DMC</a></li>
<li><a href="Differential_pulse-code_modulation" title="Differential pulse-code modulation">DPCM</a></li>
<li><a href="Grammar-based_code" title="Grammar-based code">Grammar</a>
<ul><li><a href="Re-Pair" title="Re-Pair">Re-Pair</a></li>
</ul></li>
<li><a href="Discrete_cosine_transform" title="Discrete cosine transform">LDCT</a></li>
<li><a href="Move-to-front_transform" title="Move-to-front transform">MTF</a></li>
<li><a href="PAQ" title="PAQ">PAQ</a></li>
<li><a href="Prediction_by_partial_matching" title="Prediction by partial matching">PPM</a></li>
<li><a href="Run-length_encoding" title="Run-length encoding">RLE</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Hybrid</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li>LZ77 + Huffman
<ul><li><a href="Deflate" title="Deflate">Deflate</a></li>
<li><a href="LZX" title="LZX">LZX</a></li>
<li><a href="Lempel%E2%80%93Ziv%E2%80%93Stac" title="Lempel–Ziv–Stac">LZS</a></li></ul></li>
<li>LZ77 + ANS
<ul><li><a href="LZFSE" title="LZFSE">LZFSE</a></li></ul></li>
<li>LZ77 + Huffman + ANS
<ul><li><a href="Zstd" title="Zstd">Zstandard</a></li></ul></li>
<li>LZ77 + Huffman + context
<ul><li><a href="Brotli" title="Brotli">Brotli</a></li></ul></li>
<li>LZSS + Huffman
<ul><li><a href="LHA_(file_format)" title="LHA (file format)">LHA/LZH</a></li></ul></li>
<li>LZ77 + Range
<ul><li><a href="LZMA" title="LZMA">LZMA</a></li>
<li>LZHAM</li></ul></li>
<li>RLE + BWT + MTF + Huffman
<ul><li><a href="Bzip2" title="Bzip2">bzip2</a></li></ul></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Lossy_compression" title="Lossy compression">Lossy</a><br>type</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Transform_coding" title="Transform coding">Transform</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Discrete_cosine_transform" title="Discrete cosine transform">Discrete cosine transform</a>
<ul><li><a href="Discrete_cosine_transform" title="Discrete cosine transform">DCT</a></li>
<li><a href="Modified_discrete_cosine_transform" title="Modified discrete cosine transform">MDCT</a></li></ul></li>
<li><a href="Discrete_sine_transform" title="Discrete sine transform">DST</a></li>
<li><a href="Fast_Fourier_transform" title="Fast Fourier transform">FFT</a></li>
<li><a href="Wavelet_transform" title="Wavelet transform">Wavelet</a>
<ul><li><a href="Daubechies_wavelet" title="Daubechies wavelet">Daubechies</a></li>
<li><a href="Discrete_wavelet_transform" title="Discrete wavelet transform">DWT</a></li>
<li><a href="Set_partitioning_in_hierarchical_trees" title="Set partitioning in hierarchical trees">SPIHT</a></li></ul></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Predictive</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Differential_pulse-code_modulation" title="Differential pulse-code modulation">DPCM</a>
<ul><li><a href="Adaptive_differential_pulse-code_modulation" title="Adaptive differential pulse-code modulation">ADPCM</a></li></ul></li>
<li><a href="Linear_predictive_coding" title="Linear predictive coding">LPC</a>
<ul><li><a href="Algebraic_code-excited_linear_prediction" title="Algebraic code-excited linear prediction">ACELP</a></li>
<li><a href="Code-excited_linear_prediction" title="Code-excited linear prediction">CELP</a></li>
<li><a href="Log_area_ratio" title="Log area ratio">LAR</a></li>
<li><a href="Line_spectral_pairs" title="Line spectral pairs">LSP</a></li>
<li><a href="Warped_linear_predictive_coding" title="Warped linear predictive coding">WLPC</a></li></ul></li>
<li>Motion
<ul><li><a href="Motion_compensation" title="Motion compensation">Compensation</a></li>
<li><a href="Motion_estimation" title="Motion estimation">Estimation</a></li>
<li><a href="Motion_vector" class="mw-redirect" title="Motion vector">Vector</a></li></ul></li>
<li><a href="Psychoacoustics" title="Psychoacoustics">Psychoacoustic</a></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Data_compression#Audio" title="Data compression">Audio</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Bit_rate" title="Bit rate">Bit rate</a>
<ul><li><a href="Average_bitrate" title="Average bitrate">ABR</a></li>
<li><a href="Constant_bitrate" title="Constant bitrate">CBR</a></li>
<li><a href="Variable_bitrate" title="Variable bitrate">VBR</a></li></ul></li>
<li><a href="Companding" title="Companding">Companding</a></li>
<li><a href="Convolution" title="Convolution">Convolution</a></li>
<li><a href="Dynamic_range" title="Dynamic range">Dynamic range</a></li>
<li><a href="Latency_(audio)" title="Latency (audio)">Latency</a></li>
<li><a href="Nyquist%E2%80%93Shannon_sampling_theorem" title="Nyquist–Shannon sampling theorem">Nyquist–Shannon theorem</a></li>
<li><a href="Sampling_(signal_processing)" title="Sampling (signal processing)">Sampling</a></li>
<li><a href="Silence_compression" title="Silence compression">Silence compression</a></li>
<li><a href="Sound_quality" title="Sound quality">Sound quality</a></li>
<li><a href="Speech_coding" title="Speech coding">Speech coding</a></li>
<li><a href="Sub-band_coding" title="Sub-band coding">Sub-band coding</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Audio_codec" title="Audio codec">Codec</a><br>parts</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="A-law_algorithm" title="A-law algorithm">A-law</a></li>
<li><a href="%CE%9C-law_algorithm" title="Μ-law algorithm">μ-law</a></li>
<li><a href="Differential_pulse-code_modulation" title="Differential pulse-code modulation">DPCM</a>
<ul><li><a href="Adaptive_differential_pulse-code_modulation" title="Adaptive differential pulse-code modulation">ADPCM</a></li>
<li><a href="Delta_modulation" title="Delta modulation">DM</a></li></ul></li>
<li><a href="Fourier_transform" title="Fourier transform">FT</a>
<ul><li><a href="Fast_Fourier_transform" title="Fast Fourier transform">FFT</a></li></ul></li>
<li><a href="Linear_predictive_coding" title="Linear predictive coding">LPC</a>
<ul><li><a href="Algebraic_code-excited_linear_prediction" title="Algebraic code-excited linear prediction">ACELP</a></li>
<li><a href="Code-excited_linear_prediction" title="Code-excited linear prediction">CELP</a></li>
<li><a href="Log_area_ratio" title="Log area ratio">LAR</a></li>
<li><a href="Line_spectral_pairs" title="Line spectral pairs">LSP</a></li>
<li><a href="Warped_linear_predictive_coding" title="Warped linear predictive coding">WLPC</a></li></ul></li>
<li><a href="Modified_discrete_cosine_transform" title="Modified discrete cosine transform">MDCT</a></li>
<li><a href="Psychoacoustics" title="Psychoacoustics">Psychoacoustic model</a></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Image_compression" title="Image compression">Image</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Chroma_subsampling" title="Chroma subsampling">Chroma subsampling</a></li>
<li><a href="Coding_tree_unit" title="Coding tree unit">Coding tree unit</a></li>
<li><a href="Color_space" title="Color space">Color space</a></li>
<li><a href="Compression_artifact" title="Compression artifact">Compression artifact</a></li>
<li><a href="Image_resolution" title="Image resolution">Image resolution</a></li>
<li><a href="Macroblock" title="Macroblock">Macroblock</a></li>
<li><a href="Pixel" title="Pixel">Pixel</a></li>
<li><a href="Peak_signal-to-noise_ratio" title="Peak signal-to-noise ratio">PSNR</a></li>
<li><a href="Quantization_(image_processing)" title="Quantization (image processing)">Quantization</a></li>
<li><a href="Standard_test_image" title="Standard test image">Standard test image</a></li>
<li><a href="Texture_compression" title="Texture compression">Texture compression</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Methods</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Chain_code" title="Chain code">Chain code</a></li>
<li><a href="Discrete_cosine_transform" title="Discrete cosine transform">DCT</a></li>
<li><a href="Deflate" title="Deflate">Deflate</a></li>
<li><a href="Fractal_compression" title="Fractal compression">Fractal</a></li>
<li><a href="Karhunen%E2%80%93Lo%C3%A8ve_theorem" class="mw-redirect" title="Karhunen–Loève theorem">KLT</a></li>
<li><a href="Pyramid_(image_processing)" title="Pyramid (image processing)">LP</a></li>
<li><a href="Run-length_encoding" title="Run-length encoding">RLE</a></li>
<li><a href="Wavelet_transform" title="Wavelet transform">Wavelet</a>
<ul><li><a href="Daubechies_wavelet" title="Daubechies wavelet">Daubechies</a></li>
<li><a href="Discrete_wavelet_transform" title="Discrete wavelet transform">DWT</a></li>
<li><a href="Embedded_zerotrees_of_wavelet_transforms" title="Embedded zerotrees of wavelet transforms">EZW</a></li>
<li><a href="Set_partitioning_in_hierarchical_trees" title="Set partitioning in hierarchical trees">SPIHT</a></li></ul></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Data_compression#Video" title="Data compression">Video</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Bit_rate" title="Bit rate">Bit rate</a>
<ul><li><a href="Average_bitrate" title="Average bitrate">ABR</a></li>
<li><a href="Constant_bitrate" title="Constant bitrate">CBR</a></li>
<li><a href="Variable_bitrate" title="Variable bitrate">VBR</a></li></ul></li>
<li><a href="Display_resolution" title="Display resolution">Display resolution</a></li>
<li><a href="Film_frame" title="Film frame">Frame</a></li>
<li><a href="Frame_rate" title="Frame rate">Frame rate</a></li>
<li><a href="Video_compression_picture_types" title="Video compression picture types">Frame types</a></li>
<li><a href="Interlaced_video" title="Interlaced video">Interlace</a></li>
<li><a href="Video#Characteristics_of_video_streams" title="Video">Video characteristics</a></li>
<li><a href="Video_quality" title="Video quality">Video quality</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Video_codec" title="Video codec">Codec</a><br>parts</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Discrete_cosine_transform" title="Discrete cosine transform">DCT</a></li>
<li><a href="Differential_pulse-code_modulation" title="Differential pulse-code modulation">DPCM</a></li>
<li><a href="Deblocking_filter" title="Deblocking filter">Deblocking filter</a></li>
<li><a href="Lapped_transform" title="Lapped transform">Lapped transform</a></li>
<li>Motion
<ul><li><a href="Motion_compensation" title="Motion compensation">Compensation</a></li>
<li><a href="Motion_estimation" title="Motion estimation">Estimation</a></li>
<li><a href="Motion_vector" class="mw-redirect" title="Motion vector">Vector</a></li></ul></li>
<li><a href="Wavelet_transform" title="Wavelet transform">Wavelet</a>
<ul><li><a href="Daubechies_wavelet" title="Daubechies wavelet">Daubechies</a></li>
<li><a href="Discrete_wavelet_transform" title="Discrete wavelet transform">DWT</a></li></ul></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Information_theory" title="Information theory">Theory</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Compressed_data_structure" title="Compressed data structure">Compressed data structures</a>
<ul><li><a href="Compressed_suffix_array" title="Compressed suffix array">Compressed suffix array</a></li>
<li><a href="FM-index" title="FM-index">FM-index</a></li></ul></li>
<li><a href="Entropy_(information_theory)" title="Entropy (information theory)">Entropy</a></li>
<li><a href="Information_theory" title="Information theory">Information theory</a>
<ul><li><a href="Timeline_of_information_theory" title="Timeline of information theory">Timeline</a></li></ul></li>
<li><a href="Kolmogorov_complexity" title="Kolmogorov complexity">Kolmogorov complexity</a></li>
<li><a href="Prefix_code" title="Prefix code">Prefix code</a></li>
<li><a href="Quantization_(signal_processing)" title="Quantization (signal processing)">Quantization</a></li>
<li><a href="Rate%E2%80%93distortion_theory" title="Rate–distortion theory">Rate–distortion</a></li>
<li><a href="Redundancy_(information_theory)" title="Redundancy (information theory)">Redundancy</a></li>
<li><a href="Data_compression_symmetry" title="Data compression symmetry">Symmetry</a></li>
<li><a href="Smallest_grammar_problem" title="Smallest grammar problem">Smallest grammar problem</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Community</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Hutter_Prize" title="Hutter Prize">Hutter Prize</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">
<ul><li><a href="Mark_Adler" title="Mark Adler">Mark Adler</a></li>
<li><a href="Phil_Katz" title="Phil Katz">Phil Katz</a></li></ul>
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